Sr Software Engineer (Brazil)

Kard is transforming customer loyalty with our rewards-as-a-service API platform. We empower our partners, from neobanks to financial institutions and beyond, to offer tailored rewards that celebrate customers' daily transactions. Backed by $30M from industry-leading investors and seasoned experts, we are reshaping the future of customer engagement.

About the Role

Design, build, and optimize the backend systems powering Kard’s transaction-linked rewards platform. You will develop high-performance services and external APIs that process transaction data in real time, ensuring secure and seamless reward delivery. The role is centered on Go in an AWS environment, with an increasing focus on EKS for container orchestration, alongside TypeScript and Serverless components that contribute to a flexible and scalable architecture.

Working closely with product, design, data, and other engineering teams, you will drive key architectural decisions, improve system reliability, and optimize developer experience. You’ll play a pivotal role in strengthening security, automation, and DevOps practices, ensuring that Kard’s infrastructure scales efficiently to support both our customers and our long-term vision.

At Kard, we value engineers who are business thinkers, pragmatic problem solvers, and strong communicators. Whether refining core services, scaling infrastructure, mentoring teammates, or shaping the future of our platform, you will have a direct impact on our technology and customers.

Responsibilities

• Design and implement scalable backend services in Go, ensuring reliability, security, and maintainability.
• Architect and maintain AWS infrastructure across multiple accounts, with increasing Kubernetes adoption, optimizing for performance, cost, resilience, team autonomy, and product innovation.
• Develop and enhance our TypeScript and Serverless systems, ensuring seamless integration with backend services.
• Improve observability, automation, incident management, and CI/CD, enabling faster iteration cycles and more reliable feature delivery.
• Work cross-functionally with engineering, product, data, and design teams to build high-performance distributed systems that align with business goals and user needs.
• Lead and participate in technical decision-making, balancing trade-offs between performance, scalability, simplicity, and business impact.
• Mentor engineers, fostering a culture of excellence, knowledge sharing, and continuous improvement while championing pragmatic, business-driven problem-solving.
• Ensure best practices in security, data protection, and compliance, proactively addressing risks that could impact product stability and customer trust.

Desired Skills

• Expertise in AWS, particularly with EKS, Lambda, RDS, S3, Cognito, and IAM.
• Fluency with distributed systems, event-driven architectures, and relational databases like PostgreSQL, optimizing for both performance and business flexibility.
• Hands-on DevOps and automation experience with Terraform, CI/CD, and observability tools like Datadog, ensuring a frictionless developer experience and rapid product iteration.
• Expertise in Go, with a track record of building scalable, production-grade applications.
• Significant experience with Kubernetes, including networking, scaling, and security best practices.
• Experience working in and maintaining TypeScript and Serverless environments, with a focus on reliability and extensibility.
• Strong problem-solving and communication skills, with the ability to align engineering work with business priorities.

Bonus Points

• Experience leading technical projects and mentoring engineers, helping bridge technical vision with product outcomes.
• Experience working with React or Python, even if not your primary stack.
• Experience with Databricks and MongoDB.
• Background in fintech, adtech, or transaction-based systems, with an understanding of how technical decisions influence business models.
• Contributions to open-source projects or active participation in the engineering community.